1. Field of the Invention
This disclosure relates generally to a railway vehicle brake system and, more particularly, to a thermally optimized train brake system.
2. Description of Related Art
Existing brake systems for heavy rail metro type train cars control the brakes on a “per car” or “per truck” basis. In this application, each truck operates independently of the other trucks on the car or train. When all of the equipment on a railway car is working, braking is primarily done via the motors of the propulsion system. The motors convert the kinetic energy of the moving train into electricity that is typically converted to heat in resistor banks or returned to the power grid. Friction brakes are applied only at high and low speeds when electric braking cannot provide sufficient brake effort.
In the event of an electric brake failure, with each truck operating independently, the friction brakes of the failed truck apply all of the required braking effort for the failed truck. This is done in order to maintain the requested overall train brake rate without imposing a speed restriction. In this case, the thermal load applied to the brake discs on the failed truck is very high, typically requiring 2 discs for each axle of the vehicle.
There is a current need for a railway vehicle brake system that reduces the amount of brake equipment on each train car. There is also a current need for a railway vehicle brake system that reduces the weight of the brake equipment. There is also a current need for a railway vehicle brake system that equalizes the wear of the brake equipment across the train cars. There is also a current need for a railway vehicle brake system that reduces the temperatures of the brake equipment.